Characterization of interface fluctuations and emission mechanisms in InGaN/AlGaN multiple quantum wells

The InGaN/AlGaN multiple- quantum- well heterostructures were fabricated by metal-organic chemical vapor deposition system. Samples were grown with different indium and aluminum content during the growth of InGaN well layers and AlGaN barrier layers. The exciton-localization effect on the performance of the samples is investigated by means of temperature-dependent photoluminescence measurements. The dependence of optical characteristics on temperature is consistent with recombination mechanisms involving band-tail states. For sample with higher indium content in the well layer, the localization effect is enhanced; in contrast, the effect is weakened for sample with higher aluminum content in the barrier layer.